Technical Field
The present invention relates to a packing box, a packing method and an unpacking method in which a packing target is transportation objects such as polycrystalline silicon or the like used as molten material when producing single crystalline silicon.
Priority is claimed on Japanese Patent Application No. 2015-137719, filed Jul. 9, 2015, the content of which is incorporated herein by reference.
Background Art
The Czochralski methods (hereinafter, the “CZ process”) is known as one of methods producing single crystalline silicon. The CZ process has an advantage in that single crystalline silicon with large-diameter and high-purity can be easily obtained without dislocation or with very few lattice defects.
In the CZ process, the single crystalline silicon is grown by melting high-purity polycrystalline silicon in a quartz crucible by a heating furnace, bringing seed crystal (i.e., single crystalline silicon) in a suspended state by a wire into contact to the molten silicon, and gradually drawing up it while rotating.
High-purity polycrystalline silicon used for the CZ process is adjusted to pieces having an appropriate size by cutting, cracking or the like from a rod of polycrystalline silicon, then wrapped and packed in order to avoid surface contamination after washing and drying processes; and finally, sent as a package.
In recent years, from the point of view of prevention of global warming, it is required for materials for wrapping or packing objects to be possible to reduce scrapping or incineration, or to reuse. Furthermore, it is required for a packing method to reduce the materials for packing as much as possible, and a packing method which can reduce environmental influence in disposal and working efficiency.
For example, in Patent Document 1, disclosed is a structure for packing objects partitioning an interior of a rectangular trunk by a lattice-like partition, disposing the objects in storage spaces of the objects partitioned by the lattice-like partition, and holding the objects in this state between upper and lower cushionings by elasticity of the upper and lower cushionings. Patent Document 1 describes that, by this structure for packing, it is expected to reduce an amount of the materials for packing and to improve a working efficiency associated with that since pellet-shaped cushioning is not used, and the objects are not individually wrapped. Furthermore by this structure for packing, it is expected to reduce material costs and forming costs since the trunk and the lattice-like partition are made of corrugated papers.
In Patent Document 2, a packing box (a packing means) storing products such as delicate equipment or delicate parts is disclosed. It is described that the packing box is provided with a bottom lid, storage cases, four corner boards disposed at four corners of the bottom lid, pads inserted between the storage cases, a top lid, and a sleeve surrounding them entirely, and it is possible to store far more products in a prescribed space by stacking the storage cases and the pads alternately.
Patent Document 3 discloses that working efficiency can be improved by forming an opening part at a side surface of a returnable box and providing an opening/closing member which can close or open the opening part when the objects are stored into and taken out from the returnable box.